6-speed in an FC..
 

I've been contemplating having my tranny rebuilt, and toying with the idea of having some different gears swapped in. I know it it possible to swap FB gears and miata gears into a N/A FC tranny. This got me thinking,.. the newer Miatas can come with an optional 6-speed. Would it be possible to swap these gears in, instead of the regular 5-speed gears? I was going to contact Rob at Pineapple, but thought Id ask first to see if anyone had any input. Thanks..

When you find out let me know. I am going to be in the process of gettin a new trany myself. This sounds lie a neat idea. Although wiht the lil power my car as 6th speed is overkill.

- James

i couldn't really imagine having another gear to wrap to redline in my FC. lol. you can barely get all the way through second without exceeding the speed limit. but if it's geared closer than the stock 5 speed that would be awesome.

Im sure it is. I personally think the gearing is a tad high ,( well at least 4th and 5th) in a stock FC. It may be fine for turbos . but with less powerful N/As, it seems to stop pulling *good* after 100mph, about the top of 3rd. The regular 5-speed miata gears are closer ratios that the FC, so Id assume the 6-speed would be even better.

Well depending on price, looks like you have might have found a nice lil project.

- James

Ive heard the the miata 6 speeds are weak. I mean, they may be fine for a n/a, but I know id like 6 gears. :D

no shit... i think i would like six gears as well.... let me know how it turns out.......

i agree with tonyturboii..

anyone considered a mazda b-series pickup transmission? i started a thread about that a long time ago.. dont remember much of it though..

(i know its not a 6 speed) but the b-series pickup tranny would be excellent for accelleration right? and possibly a tad more durable than a stock FC tranny? comments anyone?

I remember Soul Assasin had a 6-Speed HKS tranny.
Check them out but I'm sure it won't be cheap.

HKS Manual Transmission
Gear Ratios: 1st 2.773; 2nd 1.984; 3rd 1.548; 4th 1.246; 5th 1.000
Price: $6357.00




I found the HKS five speed at CS not 6 but it looks to be better than stock ratios.

Santiago

i wouldnt get the HKS anyway, i wold probably go with a Jerico and have 100000000 gears to chose from. They dont make a 6 speed that i know of, but who needs overdirve?

Mayhaps it be possible to swap in the RX-8 6-speed into an FC? Who knows...? We might find out in a few months. ;)

I am putting a 6 speed in my 1987 FC.

http://www.speakeasy.org/~andrewb/icons/headbanger.gif

Andrew

The 6 speed miata trannies are plenty strong enough for and NA rotary. A local rotor truck runs the miata tranny with his 175hp NA motor and its so much fun with those close gear ratios. Only problem is that the miata tranny is a different length, so the shifter comes through at a different spot. Otherwise it bolts right up. Granted this was on a rotortruck, so making it fit is simply as cutting a new hole in the floor for the shifter to go through, then cover the old one. Hope that helps some!

Graham

and to think some people say Miata's aren't good for anything, lol :D

a good friend of mine has a 91 miata and his gears are wayyy shorter than my series5 NA gears. he has that greddy 15g turbo kit and his gears may even be a little *too* short for that much power. his 1st gear is pretty much useless, but its geared just right for highway pulls and such.
i think the gears would be perfect for an FC.

Yeah, 6-speed dogmission, sold it though.

didn't sean (scathcart) have a 6speed in his FC before he got rid of it? can't remember...

I emailed Pineapple, Ill let you guys know what he says.

http://www.gurumotorsports.com/

These guys will build a dog engaged transmission using a TII case. Close ratio with 5th gear 1:1.

Well, my car is still street driven and on long trips sometimes, so I would still like an overdrive.

i'm pretty sure the 6 speed isn't an in house tranny. it's not made by mazda iirc. if it is, i'm wrong :)

what is a dog engaged transmission?

damn, I should know these things.......I mean I work at a transmission shop :D

a straight cut gear box

i dont think there is a point in spending that extra money!! wouldnt really ever use 6 gear

Well if 1st-5th were actually usable, the 6th would serve as the overdrive. Im actually going to try and look up the ratios for the 6-speed now...

The Miata six speed is a completely different tranny from the 5 speed - which is otherwise known as the Mazda type 'M' tranny, and is found with different bellhousings and other minor detail changes in many Mazda products from early seventies to present. This is why there is some swap-ability between the 5-speed models. See Felix Miata's FAQ for details on the type M, and the TII type R as well.
The six speed is made by Aisin, it has a different case, you'd have to fabricate mounts, bellhousing adapter, driveshaft, and work out the shifter location.

the "dog gears" in dogmatic transmissions are the syncros. the syncros in them are like the tops of castles. normal syncros engage by turning until they match up, then its like the two pieces just fit together, then you're in your gear. with dogmatic's the little "teeth" on these syncros are massive so you dont need to disengage the clutch when you bang gears (the syncro teeth are much much larger and grab like no matter what)

I think he was running a richmond 6 speed. I can ask him. That car was just sick.

so the dogmission in other words, means no clutch needed? that would be sweet :D

So you basically just bang through the gears and no clutch pedal? That would be sweet, and hella fast shifting (that's the point, I know...), but the clutch pedal is all part of the fun! I would feel like I was driving a manu-matic... :(

you can use a clutch or not, its your choice. it will wear quicker if you dont use the clutch though

Instead of a fine toothed splines to engage the sliders, they use big wide dogs with extra backlash clearance for quick hard clutchles shifts.

Damn - I type too slow - everyone jumped on that one!

From what I've seen & heard many drivers still give the clutch a short tap just out of habit, and of couse you still may need to feather the throttle to keep traction.

I just wish I had the budget for that kind of horsepower..

I would love a 6spd I was actually just thinking this as I was driving on I5 yesterday in fith gear hittin fuel cut:( Besides one more gear to grab:)

haha i don't think i could hit 5th in ottawa w/o getting stopped (redlining of course)

However.. anyone ever driven the 509 off of HW 7?? :D :D

no cops.... only passed one in 3 years of going there

I read somwhere that you could fit a Supra 6 speed box to a seven without major mods?

Has anyone seen or done this?

Chris

that'd be cool.

You can _always_ use another gear, even if it's just another even wider gear on top of fifth, for economy and sound purposes. To cruise on the highway, for instance.
If they were close ratio, that'd be cool too, but for Turbo cars there's almost too much torque to be usefull.

There was a video floating around a while back of a guy with a racing tranny it was a dogbone "dog gear" tranny and it was a fast shiftin bitch but very loud. Lotta tranny whine with em. I'm on vacation now but if no one has posted the video I'll post it Tuesday when I get back.

all dog gears whine. because there is only 1 tooth engaged at a time. with a helical gear box you have 2 or more teeh engaged at any given time so the meshing of the two gears is silent. revers is a straight cut gear, drive around in it for a little bit, listen to it.

Cool

I heard about the supra 6-speed, but it was in an FD from what I remember. I also remember someone saying it was hard to use it in 6th at about 60 because the revs were around 1200!

Nice!

I heard 6th gear is for Crusing at top end and there is no rear perpose for it? This was of a Guy with a 600bhp Supra.

What exactly do they do? drop the Lower ones and then fit a diffrent Final drive to make it rapid of the line while keeping the top end? if so wont you loose time shifting gear all the time?

Chris

Same deal with the C5 Vette and Viper 6 Speeds. The C5 nor the Viper can pull 6th. Your going as fast as the car will go wound out in 5th cause when you shift to 6th it'll slow down. Just a hwy gas saver gear. Both those cars only rapping 1000 or so at 70mph in 6th.

i would like to have a 6 speed tranny too, this would make mondo fun, lemme know how it goes i WILL be interested!!PEACE!!

i have the same tranny as those cars in my 69 camaro (the same gear ratios) and it is KICK ASS b/c i have 4.11 rear end so i can pull INSANE top speeds :D :D :D

when you go forward it sounds like your going reverse